Hey can I get a general survey of the fastest speed your 700-r4 will still downshift into 1st.

Thanks
John

 

mine i think is like 10-15mph cuz first only goes to 30 and it goes quick with 3.27's.

 

AHMEN to that! About 8 mph for me. If mine shifts into 2nd at ALL you can forget about a downshift. My first is good to 47 mph (3.27s @ 6700) so you can see why it ticks me off. If I let it part throttle upshift, I have to go from 12 mph to 75 without a shift. Might as well have a damn powerglide. Fixes anyone???
Here's what it looks like starting off in first:Video
2-3 upshift is still too early also.

 

Mine won't downshift to first unless you come to stop. That's a good thing, because with 4.11 gears, first is good to about 25 mph under half throttle. Manually downshifting into 1st at any speed over 8 mph will violently break loose the tires. Of course that tranny is sitting on the garage floor while I do my TKO swap.

 

With 3.08 gears and a 5,800 RPM shift, my first gear was good to about 60 mph. Second was good to 100 MPH. The 2-1 downshift would happen at speeds under 45 MPH. I could get a 3-2 downshift at 80+ MPH.

With 3.73 gears I can get to 45 in 1st and 85 in 2nd. I can get a 2-1 downshift at 30 MPH and a 3-2 downshift at 65.

 

At first these numbers didn't make sense. Then it dawned on me that this is a van and it probably has a pickup truck transmission in it. I think Fast is onto something. I seem to remember that trucks downshift just fine for towing. Maybe we could see what differences there are in the truck transmission because it's become abundantly clear that the F-body's 700R4 is very different in this respect ie: won't downshift to first.
Anyone??
I think GM made the trans control valve different to keep from throwing the back end around on the F-bodys when it rains. (we all know this happens even without a suprise 2-1 downshift)

 

Adjusting the tv cable will help force a downshift. You just have to do it little by little so that you don't get it so tight that the tranny won't up shift. My Camaro will down shift from 2nd back to first at any speed up to 26 mph.

 

The last thing you want to be doing is adjusting the TV cable to move shift points. It has one and only one right spot, if its not there your risking burning up your trans as you wont have the correct line pressures.